scholarly journals Resonances, metastable states and exponential decay laws in perturbation theory

1990 ◽  
Vol 132 (1) ◽  
pp. 177-188 ◽  
Author(s):  
Walter Hunziker
Keyword(s):  
Perturbation Theory ◽  
Exponential Decay ◽  
Metastable States

scholarly journals DECAY RATES OF METASTABLE STATES IN CUBIC POTENTIAL BY VARIATIONAL PERTURBATION THEORY

1996 ◽  
Vol 11 (24) ◽  
pp. 4383-4399 ◽  
Author(s):  
H. KLEINERT ◽  
I. MUSTAPIC
Keyword(s):  
Perturbation Theory ◽  
Decay Rates ◽  
Metastable States ◽  
Energy Eigenvalues ◽  
Variational Perturbation Theory ◽  
Rotation Method ◽  
Complex Eigenvalues ◽  
Coordinate Rotation ◽  
Variational Perturbation ◽  
Wkb Expansion

Variational perturbation theory is used to determine the decay rates of metastable states across a cubic barrier of arbitrary height. For high barriers, a variational resummation procedure is applied to the complex energy eigenvalues obtained from a WKB expansion. For low barriers, the variational resummation procedure converts the non-Borel-summable Rayleigh-Schrödinger expansion into an exponentially fast convergent approximation. The results in the two regimes match each other well and yield very accurate imaginary parts for the energy eigenvalues. This is demonstrated by comparison with the complex eigenvalues obtained from solutions of the Schrödinger equation via the complex-coordinate rotation method.

scholarly journals Beyond Mapping Functions and Gradients

2021 ◽  
Author(s):  
Jean-Pierre Barriot ◽  
Peng Feng
Keyword(s):  
Perturbation Theory ◽  
Exponential Decay ◽  
Base Case ◽  
Microwave Propagation ◽  
Orthogonal Functions ◽  
Mathematical Basis ◽  
Mapping Functions ◽  
Alternative Approach ◽  
Propagation Delays ◽  
The Sixties

Mapping functions and gradients in GNSS and VLBI applications were introduced in the sixties and seventies to model the microwave propagation delays in the troposphere, and they were proven to be the perfect tools for these applications. In this work, we revisit the physical and mathematical basis of these tools in the context of meteorology and climate applications and propose an alternative approach for the wet delay part. This alternative approach is based on perturbation theory, where the base case is an exponential decay of the wet refractivity with altitude. The perturbation is modeled as a set of orthogonal functions in space and time, with the ability to separate eddy-scale variations of the wet refractivity.

A Perturbation Theory for the Population of Atomic Energy Levels in Non-Lte Plasmas

1988 ◽  
Vol 102 ◽  
pp. 343-347
Author(s):  
M. Klapisch
Keyword(s):  
Perturbation Theory ◽  
Small Parameter ◽  
Classification Scheme ◽  
Sum Rules ◽  
Energy Levels ◽  
Natural Classification ◽  
Quantum Numbers ◽  
Formal Expansion ◽  
Atomic Energy Levels ◽  
As Effects

AbstractA formal expansion of the CRM in powers of a small parameter is presented. The terms of the expansion are products of matrices. Inverses are interpreted as effects of cascades.It will be shown that this allows for the separation of the different contributions to the populations, thus providing a natural classification scheme for processes involving atoms in plasmas. Sum rules can be formulated, allowing the population of the levels, in some simple cases, to be related in a transparent way to the quantum numbers.

LASER-INDUCED METASTABLE STATES IN AMORPHOUS SEMICONDUCTORS

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-395-C4-398 ◽  
Author(s):  
M. Wautelet ◽  
R. Andrew ◽  
M. Failly-Lovato ◽  
L. D. Laude
Keyword(s):  
Amorphous Semiconductors ◽  
Metastable States

Energy, Information, and Superluminal Speed in Quantum Electrodynamics

2020 ◽  
pp. 27-33
Author(s):  
Boris A. Veklenko
Keyword(s):  
Electromagnetic Field ◽  
Perturbation Theory ◽  
Quantum Electrodynamics ◽  
Excited Atom ◽  
Standard Quantum ◽  
Energy Information

Without using the perturbation theory, the article demonstrates a possibility of superluminal information-carrying signals in standard quantum electrodynamics using the example of scattering of quantum electromagnetic field by an excited atom.

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